Rotary pump



2 Sheets-Sheet l Oct. 2, 1928.

G. E. GOODRIDGE ROTARY PUMP Filed July '7, 1926 wha 'Il'f Patented Oct.2, 1928.

UNITED STATES PATENT OFFICE.

GEORGE E. GOODRIDGE, OF READING, MASSACHUSETTS, ASSIGNOR, BY MESNEASSIGN- MENTS, TO ARTHUR H. BALLARD, INCORPORATED, 0F BOSTON,MASSACHUSETTS,

A. CORPORATION OF MASSACHUSETTS.

ROTARY PUMP.

Application illed Iuly 7,

This invention relates to rotary pumps which may be used for pumping agreat variety of liquids and gases or a mixture of the two. This type ofpump may be particularly useful in connection with an oil burning systemfor pumping oil or oil and air to the burner.

Amon the objects of the invention are: To provide a pump in which theWear may be taken care of and compensated for Without the use ofexpensive apparatus; to provide an extremely noiseless pump such aswould not be objectionable in the event of its use in connection withdomestic oil burner installations; to eliminate knocking; to provide anaccurate and sensitive control on the output of the pump Without varyingthe speed of the driving means; to provide a means for preventingleakage from the pump -Without the use of packing; to provide positivemeans for keeping the blades in contact with the side walls of the pumpchamber which means are not liable to get out of order and which aresimple to construct and effective in operation: to provide blades whichare reversible so that the pump may be taken apart and assembled byunskilled persons Without rendering it inoperative; to provide anarrangement and design of the parts of the pump that will tend toequalize the Wear of the blades; and generally to improve the efficiencyof construction and use of pumps of this character.

Further objects and advantages of the present construction Will beapparent as the description proceeds and Will be specifically pointedout in the appended claims.

In the drawings 1n which are shown the details of certain embodiments ofmy invention by Way of example,

Fig. 1 is an end elevation viewed from the left side of Fig. 2;

Fig. 2 is a side elevation of the device;

Fig. 3 is a central, sectional elevation showing one end of a pumpembodying a modified construction;

F ig. 4 is a transverse section taken on the line l1*4 of Fig. 5;

Fig. 5 is an axial section taken on the line 5-5 of Fig. 4;

Fig. G is a development of a portion of the sleeve which lines the pumpcasing; and

Fig. 7 is an exaggerated diagrammatic 1926. Serial No, 120,952.

sectional View of a part of the device to show the operation.

The pump may comprise a central casing which may be provided at eitherend with end closure plates 2 and 3 attached to the casing 1 in anysuitable manner, as, for example, by means of bolts 4. These bolts maybe inserted loosely through holes in the end plates 1 and 2 and screwedinto the casing 1'. By making the holes in the end plates slightlylarger than the bolts the position of the casing 1 may be shiftedrelatively to one or both of the end plates to compensate for wear andto adjust the rotor, which is journalled in suitable bearings in the endplates, accurately Within the casing. It is to be understood, however,that any other desired means for so adjusting the bearings relatively tothe central casing may be employed. End plates 2 and 3 may be providedWith feet 5 and 5 for supporting the pump or with any other suitablemeans of support. Due to the friction which is necessarily incident topacking for the shafts of pumps and other devices, it is desirable touse as little of this packing as possible to obtain the maximummechanical efficiency. For this purpose one end plate of the pump may beprov1ded with a closed end bearing for the rotor thus Wholly doing awaywith packing at that point. In this instance end plate 2 is shownprovided with an integral boss 6 which may be additionally supported byan integral vertical strengthening rib 7 from the foot 5. The boss 6 isprovided with a bore 8 running part Way in from the face thereof whichcontacts with casing l, the bore terminating in an enlarged portion 9,which may be provided with any suitable means for lubrication (notshown).

1n order to eliminate the packing on the other bearing for the shaft 10and at the same time to prevent leakage along the shaft of oil or otherHuid being pumped, it has been found advantageous to connect a portionof the bearinnr at or around the shaft with the suction side of thepump. In the event that oil is being pumped this is practicallyadvantageous for the reason that oil which might tend to leak out alongthe shaft will lubricate the bearing and then be drawn into the suctionside of the pump Without the provision of other lubricatin means for thebearings. It is also desirab e in pumps which are adapted to be drivenby a substantially constant speed drive to have some means ofcontrolling the fluid output of the pump. This may advantageously bedone by providing a valve controlled by-pass between the inlet andoutlet passages of the pump. In the present device both of these objectsare accomplished by practically a single integral device which isincorporated in the end plate 3. The pump casing 1 (see Fig. 4) isprovided with an inlet passage 11 and an outlet passage 12 which may beconnected to any suitable supply and delivery points by pipes 13 and 14respectively. One or both ot these passages may be provided with angularpassages such as is shown, for example, at 15 for other or additionalinlet or outlet pipes as desired. `When not being used, the additionalpassages may be closed by screw plugs as shown at 16. The inlet andoutlet ducts have connected to them (see Figs. 1 and 2) comparativelysmall duets 17 and 18 respectively extending axially of the pump, whichducts have portions in the casing 1 and other portions in the end plate3 which portions register with each other. The end plate 3 may beprovided with sintable raised or thickened portions to accommodate theducts 17 and 18 and also those to be described. These ducts terminate inchambers in the end plate 3 which are provided at their lower portionswith conical seats 21 and 22 respectively. Valves 23 and 24 are adaptedto fit in seats 21 and 22 respectively and may he controlled in anysuitable manner, as, for example, by screw bolts 25 and 26 respectivelyintegral therewith which may be provided with any desired means forturning them, as, for example, the screw driver slots shown. The endplate 3 is provided with a boss 27 which may be supported by a rib 28 ina similar manner to boss 6 and rib 7 described above. The boss 2T isprovided with a bore 29 extending completely therethrough, the Wholeforming a bearing for that part of the shaft 10. In Figs. 1 and 2 thereis shown Within the boss 27 and surrounding the bore 29 an annulargroove 3() which is connected by passages 31 and 32 with the valvechambers below the valve seats thereof.

The operation of the device. thus far described is as follows: In theevent that it is desired to cut down the output of the pump, both thevalves 23 and 24 are opened to bypass a desired amount of the Huid beingpumped from the outlet of the pump to the inlet. However, if it is notdesired to cut down the output in this way, the valve 24 connecting thegroove 30 in the bearing to the outlet side of the pump is closed.Normally the valve 23 connecting the groove 30 to the inlet side of thepump is open. This will connect the groove 30 through the passage 31,valve chamber and passage 17 to the inlet chamber 11 Where a suctionexists which will draw into the inlet chamber of the ump any of thefluid being pumped Whfci might otherwise esrape along the shaft 10. Inpractical operation valve 23 will be maintained open during all the timethe pump is in use so that a continuous suction is maintained on thebearing and valve 24. only open to a slight extent when it is desired tobv-pass a portion of the Huid being pumped. The valve 23 is only closedwhen the pump is shut down so as to prevent any fluid which might be inthe inlet chamber of the pump from leaking out along the shaft andcausing a possible tire risk in the case of a pump for oil.

Figure 3 shows a modification of the device illustrated in Figs. 1 and2, and in particular shows a modified form of end plate 3 which isprovided with a boss 27 which in turn provides a bearing for the shaftl0, as in the first described construction. In this modification,however, the inlet pipe 3 is connected to the bottom of :in inletchamber comprising a circumferential groove or cnlai'genicnt 33 entirelysurrounding the rotor shaft 10. This inlet chamber 33 is connected tothe suction chamber oli the pump by iucans of the axially extendinglpassage 34, the radial passage 35, and the communicating` axiallyextending passage 33 opening into the suction chamber. A valvecontrolled by-pass from thc outlet side it the pump to the suctionpassage 35, similar to that described iu connection with Figs. 1 and 2,may be employed if desired, o1 the construction ot Fig. 3 may bceinplovcd without such by-pass. Accordingly, as the pump is rotated theliquid fuel is drawn under suction into the inlet chamber 33 about thebearing portion of the rotor shaft and into the suction chamber of thepump and delivered under pressure through the delivery pipe 14. Duringsuch time as the pump is in operation there is no tendency for the oilor other liquid employed to escape from the end plate 3 about the iotorbearings. and when the operation ot the pump is stopped any residualliquid in the suction chamber will drain back into the suction pipe.Accordingly, it is possible to operate the pump :is so constructedwithout the necessity of packing for the rotor bearings.

The pump casing is irovided with a substantially cylindrical chamberwhich in the present instance is provided with a substantiallycylindrical sleeve or lining member 36. The inlet passage (either 11 inFig. 4 or 35 in Fig. 3) may be connected to a substantially arcuatechamber 37 extending almost from end to end of the casing 1 of the pumpand slightly less than 90o about its periphery. Outlet chamber 12 isprovided with a substantially similar arcuate chamber 3S. The liningmember 36 which is shown extended on F ig. 6 is provided with aplurality of small staggered openings, certain of which are arranged inparallel rows 3f) and 40 on either side of and closely adjacent to adividing wall 4l between chambers 3T and 38. The remainder of theopenings from and to the inlet and outlet chainbers respectively aresituated fairly evenly over the whole area of these chambers. Thisarrangement of holes is for the purpose of iroviding at all times asubstantial support or the`blades. as a single elongate opening wouldpermit the blades to wear to a greater extenton the ends which wouldeventually cause the portion of the blade opposite the opening to dropinto it on cach revolution and cause knocking and irregular operation.

A rotor 42 is mounted in any suitable manner upon the shaft l() and maybe integral therewith. This rotor is provided with two or more radialslots 43 extending from end to end thereof. In the present embodimenttwo slots are shown diametrieally opposite each other, this being thepreferred construction. The slots 43 are adapted to hold blades 44loosely slidable therein.

Means are provided for holding the blades in engagement with the insideof the sleeve member 36, such means in the present case taking the formof a cup member 45 and a plug member 46 having a part extending looselyinto the cup member 45, members 45 and 46 being urged apart by asuitable compressible member, as, for example, a spiral spring 47arranged wholly within the cup 45. These members are adapted to becontained in suitable bores extending between the slots 43 andpreferably substantially perpendicular to the axis of the rotor. It hasbeen found by experiment that this form of device for urging the platesagainst the sides of the casing is very satisfactory for the reason thatthe spring or other extensible device is entirely enclosed and the holeis not liable to get stuck or out of order, and furthermore, the partsare protected against dirt and other foreign material lodging therein.

An important feature is the provision for eliminating that noise whichmanifests itself in pumps of this type by a knocking effect. The lineoftangency 50 between the eccentrically mounted rotor 42 and the lining,at the dividing wall 41, provides a, seal between the inlet and outletchambers of the pump, across which the motor blades move with a wipingaction. y

Since the rotor contacts with the walls of the pump chambersubstantially in a single line of tangency, which is separated by anappreciable distance from the nearest edge of the outlet 40, there isformed between the outlet port and the line of tangency a smallclearance space bounded by the inner surface of the lining and the outersurface of the rotor, which space gradually decreases in size as itapproaches the line of tangency where the walls of the lining and therotor COllVQlgU.

In pumps of this type as heretofore constructed, the effect produced bythe blade in closing theoutlct opening is to close also this smallclearance space, trapping therein a small quantity of the oil or otherliquid being pumped. The trapped liquid thus becomes confined in aclosed space of triangular like cross section bounded by the advancingface of the blade, by the outer surface of the rotor, and by that partof the inner surface of the lining located between the line of tangencyand the wipingr edge of the blade. With the continuing advance of theblade f rom the outlet port toward the line of tangency, the volume ofthis space confining the trap ed liquid becomes progressively less an(entirely disappears as the blade reaches the point of tangency. Thepressure on this trapped liquid accordingly increases as the bladeapproaches the point of tangency and is not relieved until the bladereleases the liquid to the suction side of the pump. The liquid, beingsubstantially incompressible, must seek relief from this increasingpressure, and this it appears to do by forcing the blade inwardly.Duringthe interval which elapses therefore between the time the bladecloses the discharge opening and the time it crosses the seal andreleases the trapped liquid to the suction side, the liquid is placedunder rapidly increasing pressure and is then suddenly released, theapparent effect being to cause the blade to move inwardly and thenoutwardly, but at all events producing a knock which is repeated eachtime one of the blades wipes over the seal.

ln the pump herein described, I have arranged the parts, including therelative proportions of the seal and the blade, so that the liquidcaught or trapped in advance of the blade on the compression side of theseal is released to the suction side of the pump just before the wipingor contacting edge of the blade reaches the point where it is effectivein cutting ofi' such trapped liquid from the ports on the compressionside, whereby such liquid is not subjected to the pressure referred toand the noise or knocking described is thereby su pressed.

This result may be secured) by various different relative arrangementsof the blade, partition wall and rotor, but herein, as illustrative ofthe broad principle, I have provided a simple but effectiveconstruction. To this end the blade 44 .has its advancing end at 48beveled or rounded on a sharp radius of curvature, so that when theblade approaches the seal and retreats within its slot, there isprovided a small, substantially triangular recess or pocket in advanceof the contacting edge of the blade, which recess is formed between therounded edge of the blade, the wall 51 of the slot 43 and the liningrsleeve 36. Preferably the blade is beveled or rounded from itscontacting edge in both directions, forwardly and rearwardly, and theblade, moreover, is of a thickness greater than that of the partitionwall between the inlet and outlet 'openings Accordingly, the distancefrom the contacting or effecting wiping edge of the blade and the sideWall 51 of the slot 43 is greater than that between the point oftangency 50 and the edge 49 of the outletgopening. i

As the rotor turns (right-handedly in Fig. 4), the advancing face of theblade and the wall 51 (see Iig. 7) of the slot 43 pass the point oftangency 5() before the contacting or effective wiping edge of the bladereaches the point 49 and before it seals off the outlet chamber of thepump to the liquid which is cau ht in advance of the contacting edge anin the triangular recess referred to. Since the wall 51 of the slot 43has then assed the point of tangency, and the perip ery of the rotor atthe end of the wall 51 1s then spaced a short distance from the sleeve36, the trapped lixluid is thereby provided with an outlet to t iesuction side of the pump before itis completely cut off.

from the compression side an accordingly, will pass into the suctionside and be recirculated through the pump By a proper selection ofclearances, this slight leakage may be reduced to an unsubstantialamount, but it results in a marked reduction in the pounding noiseincident to the operation of thefpump, which noise is due mainly to thepressure exerted on the small confined slug of oil if the outlet openingis closed before the point of tangency is reached.

While I have shown and described certain definite embodiments of theinvention, I do not wish to be limited to the shape, size, design orconstruction of the embodiment shown but merely by the scope of theappended claims.

Claims:

1. A rotary fluid pump comprising a casing having a substantiallycylindrical chamber therein, a rotor mounted eccentrically of saidchamber, one or more pairs of diametrically opposite radial slots insaid rotor, blades in said slots, transverse bores connecting said slotsand expansible members in said bores and exerting an upward pressure onsaid opposite blades, each of said cxpansible members comprising a cupmember having a compressible member therein and a plug member having apart fitting into said cup member and resting against said compressiblemember.

2. A rotary fiuid pump comprising a casing having a substantiallycylindrical chamber therem, a rotor mounted eccentrically of saidchamber, one or more airs of diametricall opposite radial slots in saidrotor, double e ged reversible blades in said slots, transverse boresconnecting said slots and eglpansible members in said bores and exertingan upward pressure on said opposite blades, each of said expansiblemembers comprising a cup member having a compression spring therein anda plug member having a part fitting into said cup member and restingagainst said compressible spring to be urged outwardly thereby.

3. A rotary r'fuel pum having inlet and outlet chambers, a cylindricalpump chamber communicating with said inlet and outlet chambers, a rotoreccentrically mounted within said pump chamber and contacting with thepump chamber between the inlet and outlet chambers to form a sealthereat, a blade carried by said rotor fand adapted to wipe over theinner surface of said cylindrical pump chamber, wheby said blade inwiping over the outlet si e of the seal carries before it a small amountof fluid, and means for relieving the increasing com ression onsaidsmall amount of fiuid by re easing the same to the inlet side of theseal be'-v fore the blade closes the compression side".

thereto.

4. A rotary fluid ump comprising a casing havin inlet an outletchambers, a central cylin rical chamber to which the inlet and outletchambers open, a rotor eccentrically mounted within said central chamberand tangent to a line thereof` to form a seal thereat, a blade in saidrotor, said blade, rotor and seal being related to each other to cause asmall amount of the fiuid being pumped to be carried ast the point oftangency to the inlet si e before closing the outlet opening on eachrvolution of the pump, whereby to prevent knocking.

5. A rotary Huid pump havingr inlet and outlet chambers, a central,cylindrical pump chamber, a rotor eccentrically mounted within the pumpchamber and substantially tangential thereto at a line between the inletand outlet thereof, a blade carried by the rotor and adapted to wipeover the inner surface of the cylindrical pump chamber. the blade actingto carry a small amount of fluid past the outlet port before the latteris cut ofi' by the wiping edge of the blade. and thej distance from theinlet port to the point of tangency beingsuch as to release said fluidto the inlet side of the pump before the blade cuts ofll said outletport.

6. A rotary fluid pump having inlet and outlet chambers, a central,cylindrical pump chamber, a rotor eccentrically mounted within the pumpchamber and substantially tangential thereto at a` line between theinlet and outlet ports thereof, a blade carried by the rotor and adaptedto wipe over the inner Surface of the cylindrical pump chamber, a slotin said rotor in which said blade slides, L the advancing portion of theedge of said blade being beveled or rounded back from its face towardits contacting or wiping portion, and the distance from the advancingface to the wiping or contacting portion of' u* its edge being greaterthan the distance from the outlet port to the point of tangency.

7. A rotary fluid pump having inlet and outlet chambers, a central,cylindrical pump chamber, a rotor eccentrically mounted f within thepump chamber and substantially tangential thereto at a line between theinlet and outlet ports thereof, a blade carried by the rotor and adaptedto wipe over the inner surface of the cylindrical pump chamber, a slotin said rotor in which the blade slides, said blade and rotor beingrelated to form a pocket or recess in advance of the effective wipingedge of the blade when the latter is in its retreated position, thedistance from the effective wiping edge of the blade to the leading endof said recess being greater than the distance from the outlet port tothe point of seal.

8. A rotary fluid pump comprising a casing having a substantiallycylindrical chamber therein, an inlet chamber and an outlet chambercommunicating with said cylindrical chamber, a wall therebetweenparallel with the axis ofsaid cylindrical chamber, a

rotor mounted eccentrically within said casing, said rotor being tangentto the inside of said cylindrical chamber along a line between the inletand outlet chambers to form a seal thereat, a slot in said rotor and ablade in said slot, the distance between the edge of the outlet chamberadjacent the point of tangency and said line being less than half thewidth of the blade.

9. A rotary fluid pump comprising a casing having a substantiallycylindrical chamber therein, an inlet chamber and an outlet chambercommunicating with said cylindrical chamber, a wall therebetweenparallel ber adjacent the point of tangency and said point being lessthan one half the width of the blade, and the edge of the blade beingcurved on a short radius of curvature whereby as the rotor turns theadvancing edge of the blade has passed the point of' tangency before thecenter line of the blade has reached the corner of the outlet opening toclose it.

l0. YA rotary pump comprising a casing, a rotor mounted eccentricallywithin said casing but contacting therewith, inlet and outlet chamberson opposite sides of said region of contact, blades in said rotor, eachblade having its edge rounded to provide substantially a line of contactwith the inner wall of said casing, the radius of curvature of the endof the blade being short to provide a small fluid pocket between thecontacting part of the blade, the side walls of' the slot and theenclosing cylindrical casing and each .blade being wider than the spacebetween the inlet and outlet chambers.

1l. A rotary liquid pump having a casina containing a pump chamber, arotor shaft provided with a bearing adjacent said pump chamber, saidcasing having a liquid suction chamber and a liquid discharge chamber, asuction space to which the bearing portion of the shaft in said casingis eX- posed, said space being connected with the liquid suction chamberby a suction conduit, and an inlet chamber adapted for connection to anextraneous source of liquid supply and connectedto said suction chamberthrough said suction space and said suction conduit.

In testimony whereof, I have signed my name to this specification.

GEORGE E. GOODRIDGE.

Patent No. 1,686, 272.

Granted October 2, im to GEGRGE E. GOODRIDGE.

lt is hereby certified that error appears in the printed specificationof tb above numbered patent requiring correction as follows:

"upward" read "outward";y and that the claims l end 2 respectively, forthe word Page 4, linee 591ml 7l,

seidLetters Patent should be read with these corrections therein `thatthe l* may conform to the record of the case in the Patent Office.

Signed and sealed this 20th day of November. A. Y? 1928.

(Seal) M. J. Moore, Acting-Commissioner of Panes..

and outlet ports thereof, a blade carried by the rotor and adapted towipe over the inner Surface of the cylindrical pump chamber, a slot insaid rotor in which said blade slides, L the advancing portion of theedge of said blade being beveled or rounded back from its face towardits contacting or wiping portion, and the distance from the advancingface to the wiping or contacting portion of' u* its edge being greaterthan the distance from the outlet port to the point of tangency.

7. A rotary fluid pump having inlet and outlet chambers, a central,cylindrical pump chamber, a rotor eccentrically mounted f within thepump chamber and substantially tangential thereto at a line between theinlet and outlet ports thereof, a blade carried by the rotor and adaptedto wipe over the inner surface of the cylindrical pump chamber, a slotin said rotor in which the blade slides, said blade and rotor beingrelated to form a pocket or recess in advance of the effective wipingedge of the blade when the latter is in its retreated position, thedistance from the effective wiping edge of the blade to the leading endof said recess being greater than the distance from the outlet port tothe point of seal.

8. A rotary fluid pump comprising a casing having a substantiallycylindrical chamber therein, an inlet chamber and an outlet chambercommunicating with said cylindrical chamber, a wall therebetweenparallel with the axis ofsaid cylindrical chamber, a

rotor mounted eccentrically within said casing, said rotor being tangentto the inside of said cylindrical chamber along a line between the inletand outlet chambers to form a seal thereat, a slot in said rotor and ablade in said slot, the distance between the edge of the outlet chamberadjacent the point of tangency and said line being less than half thewidth of the blade.

9. A rotary fluid pump comprising a casing having a substantiallycylindrical chamber therein, an inlet chamber and an outlet chambercommunicating with said cylindrical chamber, a wall therebetweenparallel ber adjacent the point of tangency and said point being lessthan one half the width of the blade, and the edge of the blade beingcurved on a short radius of curvature whereby as the rotor turns theadvancing edge of the blade has passed the point of' tangency before thecenter line of the blade has reached the corner of the outlet opening toclose it.

l0. YA rotary pump comprising a casing, a rotor mounted eccentricallywithin said casing but contacting therewith, inlet and outlet chamberson opposite sides of said region of contact, blades in said rotor, eachblade having its edge rounded to provide substantially a line of contactwith the inner wall of said casing, the radius of curvature of the endof the blade being short to provide a small fluid pocket between thecontacting part of the blade, the side walls of' the slot and theenclosing cylindrical casing and each .blade being wider than the spacebetween the inlet and outlet chambers.

1l. A rotary liquid pump having a casina containing a pump chamber, arotor shaft provided with a bearing adjacent said pump chamber, saidcasing having a liquid suction chamber and a liquid discharge chamber, asuction space to which the bearing portion of the shaft in said casingis eX- posed, said space being connected with the liquid suction chamberby a suction conduit, and an inlet chamber adapted for connection to anextraneous source of liquid supply and connectedto said suction chamberthrough said suction space and said suction conduit.

In testimony whereof, I have signed my name to this specification.

GEORGE E. GOODRIDGE.

Patent No. 1,686, 272.

Granted October 2, im to GEGRGE E. GOODRIDGE.

lt is hereby certified that error appears in the printed specificationof tb above numbered patent requiring correction as follows:

"upward" read "outward";y and that the claims l end 2 respectively, forthe word Page 4, linee 591ml 7l,

seidLetters Patent should be read with these corrections therein `thatthe l* may conform to the record of the case in the Patent Office.

Signed and sealed this 20th day of November. A. Y? 1928.

(Seal) M. J. Moore, Acting-Commissioner of Panes..

